Am I being unfair or unreasonable here? (Please read detail)

My son lives far away with my ex. My daughter lives with me. Last year I traveled there and bought my son a $4300.00 race bike. After several months, my son injured his back (not on that bike but on another bike I bought) and didn’t ride for some months. The race bike was stolen. I have been told that it was taken from his home where he lives with his dad, my ex. They have a great big dog. I understand there was an insurance payment. I am being asked to send $2500.00 over to help buy a new bike. My now husband says no, it is their fault for not protecting the bike against theft, that we don’t know how much my ex really got from the insurance, and that it should be on him (my ex) to replace because it was his property and he is the adult and should have taken greater care to protect his property from thieves. Now my ex is angry at my son and wants him to sell his computer, game console and other personal items I bought for him and send the money to us because he feels like we are inferring that he did something wrong -like an insurance rip-off.I told my son not to sell anything. Is my present husband being fair here?